57984-70-0Relevant articles and documents
Unified Approach to Furan Natural Products via Phosphine-Palladium Catalysis
Chen, Violet Yijang,Kwon, Ohyun
supporting information, p. 8874 - 8881 (2021/03/17)
Polyalkyl furans are widespread in nature, often performing important biological roles. Despite a plethora of methods for the synthesis of tetrasubstituted furans, the construction of tetraalkyl furans remains non-trivial. The prevalence of alkyl groups in bioactive furan natural products, combined with the desirable bioactivities of tetraalkyl furans, calls for a general synthetic protocol for polyalkyl furans. This paper describes a Michael–Heck approach, using sequential phosphine-palladium catalysis, for the preparation of various polyalkyl furans from readily available precursors. The versatility of this method is illustrated by the total syntheses of nine distinct polyalkylated furan natural products belonging to different classes, namely the furanoterpenes rosefuran, sesquirosefuran, and mikanifuran; the marine natural products plakorsins A, B, and D and plakorsin D methyl ester; and the furan fatty acids 3D5 and hydromumiamicin.
Stereoselective Synthesis of the C1-C22 Carbon Framework of (-)-Amphidinolide K
Chandankar, Somnath S.,Raghavan, Sadagopan
, p. 9584 - 9602 (2019/09/06)
Two stereoselective routes to the C7-C22 subunit of amphidinolide K are disclosed. Jacobsen's hydrolytic kinetic resolution and Sharpless' asymmetric dihydroxylation reactions have been employed for the construction of the tetrahydrofuran ring. The C10-C1
Propene as an Atom-Economical Linchpin for Concise Total Synthesis of Polyenes: Piericidin A
Trost, Barry M.,Gholami, Hadi
supporting information, p. 11623 - 11626 (2018/09/21)
A concise and convergent total synthesis of piericidin A is disclosed. The synthesis hinges on the utilization of propene as a synthetic linchpin to merge the properly elaborated alkyne fragments, leading to the 1,3,6-triene motif of piericidin A. Utilization of propene as a unique alkene, capable of sequential coupling with two alkynes, is further illustrated in the context of various 1,3,6-triene products. The latter process proceeds with high atom economy and efficiently gives rise to complex frameworks from readily accessible alkyne substrates. This strategic C-C bond formation offers an orthogonal paradigm in the design of synthetic routes, leading to higher step economy and more efficient syntheses of polyunsaturated natural products.
Spectroscopy and Photochemistry of Triplet 1,3-Dimethylpropynylidene (MeC3Me)
Knezz, Stephanie N.,Waltz, Terese A.,Haenni, Benjamin C.,Burrmann, Nicola J.,McMahon, Robert J.
, p. 12596 - 12604 (2016/10/07)
Photolysis (λ > 472 nm) of 2-diazo-3-pentyne (11) affords triplet 1,3-dimethylpropynylidene (MeC3Me, 33), which was characterized spectroscopically in cryogenic matrices. The infrared, electronic absorption, and electron paramagnetic resonance spectra of MeC3Me (33) are compared with those of the parent system (HC3H) to ascertain the effect of alkyl substituents on delocalized carbon chains of this type. Quantum chemical calculations (CCSD(T)/ANO1) predict an unsymmetrical equilibrium structure for triplet MeC3Me (33), but they also reveal a very shallow potential energy surface. The experimental IR spectrum of triplet MeC3Me (33) is best interpreted in terms of a quasilinear, axially symmetric structure. EPR spectra yield zero-field splitting parameters that are typical for triplet carbenes with axial symmetry (|D/hc| = 0.63 cm-1, |E/hc| = β 0 cm-1), while theoretical analysis suggests that the methyl substituents confer significant spin polarization to the carbon chain. Upon irradiation into the near-UV electronic absorption (λmax 350 nm), MeC3Me (33) undergoes 1,2-hydrogen migration to yield pent-1-en-3-yne (4), a photochemical reaction that is typical of carbenes bearing a methyl substituent. This facile process apparently precludes photoisomerization to other interesting C5H6 isomers, in contrast to the rich photochemistry of the parent C3H2 system.
MACROCYCLIC PICOLINAMIDES AS FUNGICIDES
-
Paragraph 0098; 0099, (2016/01/25)
This disclosure relates to macrocyclic picolinamides of Formula (I) described herein, wherein X, Y, R1 and R2 are as defined herein and to their use as fungicides in a formulation comprising a phytologically acceptable carrier. Also provided are methods of using compounds of Formula (I) in combination with other pesticides including fungicides, insecticides, nematocides, miticides, arthropodicides, bactericides, and combinations thereof.
Torquoselectivity in the nazarov reactions of allenyl vinyl ketones
Morgan, Timothy D. R.,Leblanc, Luc M.,Ardagh, Giselle H.,Boyd, Russell J.,Burnell, D. Jean
, p. 1042 - 1051 (2015/01/30)
Nazarov reactions mediated by BF3-etherate of a series of carbon-substituted allenyl vinyl ketones provided intermediates in which substituents on the termini of the allenes had rotated away from the vinyl moieties, and these intermediates were
Total synthesis of carolacton, a highly potent biofilm inhibitor
Schmidt, Thomas,Kirschning, Andreas
supporting information; experimental part, p. 1063 - 1066 (2012/03/11)
Metals are the key players in the synthesis of caralacton, a strong inhibitor of bacterial biofilms. The total synthesis is based on several metal-mediated key transformations such as the Ley and the Duthaler-Hafner aldol reactions, the Marshall reaction and Breit's substitution, as well as the Nozaki-Hiyama-Kishi and Negishi-Fu C-C coupling reactions. Copyright
Highly stereoselective C-C bond formation by rhodium-catalyzed tandem ylide formation/[2,3]-sigmatropic rearrangement between donor/acceptor carbenoids and chiral allylic alcohols
Li, Zhanjie,Parr, Brendan T.,Davies, Huw M. L.
supporting information; experimental part, p. 10942 - 10946 (2012/08/07)
The tandem ylide formation/[2,3]-sigmatropic rearrangement between donor/acceptor rhodium carbenoids and chiral allyl alcohols is a convergent C-C bond forming process, which generates two vicinal stereogenic centers. Any of the four possible stereoisomers can be selectively synthesized by appropriate combination of the chiral catalyst Rh2(DOSP)4 and the chiral alcohol.
Palladium(II)-catalyzed dicarboxymethylation of chiral allylic alcohols: Chirality transfer affording optically active diesters containing three contiguous chiral centers
Hamed, Othman,Henry, Patrick M.,Becker, Daniel P.
supporting information; experimental part, p. 3514 - 3517 (2010/09/05)
This manuscript describes the extension of Stille's palladium-catalyzed olefin dicarbonylation reaction to chiral allylic alcohols with chirality transfer to afford the corresponding chiral alcohol functionalized with bis-carbomethoxy esters, containing three contiguous chiral centers, in good to excellent diastereoselectivities (78-98%).
